A bolometer can be used to detect and measure energy (or power) of incident electromagnetic radiation.
Superconductor-based bolometers can exhibit high sensitivity and fast response.
One form of superconductor-based bolometer is a hot-electron bolometer (HEB) which comprises a superconductor and a pair of normal metal contacts. An example of a hot-electron bolometer is described in JP 2004 88852 A.
Another form of superconductor-based bolometer is a cold-electron bolometer (CEB) which comprises a normal metal-insulator-superconductor (NIS) tunnel junction, for example, as described in U.S. Pat. No. 5,634,718 A. The metal region serves as an absorber which is cooled using the tunnel junction.
Yet another form of superconductor-based bolometer is a transition-edge sensor (TES) which is similar to the cold-electron bolometer but which employs direct dc heating. An example of a transition-edge sensor is described in US 2010 304977 A1.
Although existing forms of bolometers which employ a normal metal and a superconductor exhibit high sensitivity and fast response, there is scope for improving performance.